PTO shaft replacement and ORC Questions

[Anonymous-0]

The splines on my PTO (52 8n) are all buggered up. That must be why the PTO pops out of gear often when I'm bush hogging the meadow.
I've been reading the archives and it appears, with luck, that the PTO shaft should just slide right out when I unbolt the four bolts.
And, yes, I know I need to park her downhill or drain the hydraulic fluid first. The fluid is fresh and clean so I don't want to replace it when I do this job. Anything else I should do while I've got the shaft out? It's leaking now so I know I need a new seal. Are new bearings included with the new shaft or should I replace them?
When I get this done, I want to finally install an ORC. The archives indicate there are various styles and qualities. Can you guys please recommend a good one? And a place to buy it?
Another question about ORCs. I read somewhere that the ORC allows the PTO shaft to free wheel if the implement exceeds the PTO speed. Is that right. I nearly always have to exceed 540 rpm when I'm mowing my meadow. It's too thick to run it so slow. It will never get the job done if I can't keep the tractor running around 1800 rpm or so. Will the ORC really keep me from doing that?
Should I also install a sleeve that totally encloses the ORC and implement shaft? Where do you get these things?

 

[Anonymous-0]

The ORC is a "check valve" it only lets power go from your tractor to the bush hog. All the power you can give it (up to the rated fail specs, usually around 2 times what yer N will do).

Then when you slow down, it doesn't let the bush hog "inertia" power (push) the tranny/wheels.

 

[Anonymous-0]

If you replace the whole shaft, it comes complete, with nothing else to buy, including all the seals and bearings. You can get a good ORC from this site, or a better one from Purvis Bearings. The ORC only comes into play when you push in the clutch, allowing the bush hog to free wheel without pushing the tractor forward into whatevewr is up there in front of you. If you run it a bit fast, it will be OK.

 

[Anonymous-0]

First, the new PTO shaft comes complete with bearing, seals & snap rings. It is likely that your jumping out of gear on the PTO is that the snap ring is out of the groove and your shaft is moving in and out because the snap ring has came out of the retaining groove. If you can pull and push your shaft in and out of your tractor by 1/8" or so would indicate this.
You have your thinking turned around. The ORC pulls your mower at what ever speed your motor turns the PTO shaft. The free wheel is when your mower is up to speed and you slow your engine down quickly or push in the clutch, it keeps the mower from backfeeding into your tractor and pushing your gearbox and wheels. It is stictly a saftey thing to make sure your tractor stops when you push the clutch in.

 

[Anonymous-0]

Dern, I'm gonna have to learn to type faster!!!

 

[Anonymous-0]

The ORC allows the <font color=red>implement drive shaft (and implement)</font> to freewheel when it exceeds the PTO speed. What you are missing is the PTO is turning at 540 RPM when the engine is running at 1800 RPM (more or less). Most 3pt mower gear boxes are rated for a MAXIMUM of 540 RPM.

TOH

 

[Anonymous-0]

After having it happen to me, I have seen several discussions on the problem of having the PTO pop out of gear. I think that would be a useful topic area.

If your PTO shift lever does not stay engaged, the problem is probably not in the PTO transmission, but rather is due to forward/aft movement of the PTO shaft itself. Grab the PTO (tractor off) and see if you can move the shaft back and forth - if so, this is almost certainly the problem. The most likely cause is a PTO connecting shaft with your implement either being to long or binding. Either case will put pressure to push the PTO shaft on the tractor forward. The reason is is able to move is that the only thing holding the tractor PTO shaft in position is the friction fit of the bearing and oil-seal sleeve.

Fortunately, the PTO shaft is extremely simple to work on - just remove the 4 bolts at the PTO shaft housing at the back of the tractor and the shaft slides right out. If you are not experiencing significant oil leaks, you may just decide to press the bearing and oil-seal sleeve back into position and re-install the PTO shaft. However, for about $20 you can replace the bearing, seal, and sleeve while you have everything in front of you (replace the gasket too). If you have the smaller 1 1/8" PTO shaft, you may want to take this opportunity to simply purchase a replacement 1 3/8" PTO shaft assembly for about $120. This will include the everything you need - just take out the 4 bolts, slide out the old shaft, slide in the new one and replace the 4 bolts, and that's it!

Before you take out those 4 bolts, you must drain the rear axle/hydraulic fluid. Some folks park their tractor on a down slope (nose down) to eliminate the need to drain the fluid (I recommend against propping up the rear wheels to put the tractor at a steep angle). If you choose the 'park on a hill' method, you are likely to drain most of your rear axle fluid into your hydraulic reservoir when you remove the PTO shaft. Make sure all your fluid levels are back to normal when you finish the job.

Oh, and don't forget to address the root of the problem - that PTO connecting shaft. Check to see that it doesn't bind or that it isn't too long for you to take tight turns before you put your tractor back to work.

Don Hoying

 

[Anonymous-0]

Man made ditch, plastic 12K rated ramps, tools i kin not live wif out. Every man needs a set of'em they are rite handy. BTW I had the pump out of this tractor do you see enny oil on the floor. The tars are 12.4's and i hate'em to dang big fer a N.

 

[Anonymous-0]

Thanks, Gentlemen. I did just go out and check the in/out play in the PTO shaft. It looks like it moves a good half inch in and out, and it's wobbly/sloppy, too. Big chunks out of the spline don't help much, I imagine. I'll probably go the easy, if more expensive route of replacing the whole shaft.
What are your thoughts on a quick release ORC versus a semi-permanent one?

 

[Anonymous-0]

Yor external pto splines have as little to do with your pto popping out of gear as your trucks paint job making the vehicle go faster or slower.

it's that in / out play ont he shaft that is causing it to pop out of gear.. bead bearing, or loose snap ring in the carrier.. etc..

Soundguy

 

[Anonymous-0]

You said, "I will never get the job done if I can't keep the tractor running about 1800 rpm..."

Think of the ORC as a "torque check valve" or a "torque diode". It only transmits torque one way;from the PTO to the implement regardless of the PTO speed. If the implenet tries to transmit torque to the PTO, the sprag clutch just ratchets and doe not allow the implement to transmit the torque to the PTO shaft. It has nothing to do with rated PTO speed. You can run your engine at 2200 rpm and your PTO speed will be above 540 and the ORC will still drive the PTO(assuming you don't have a speed limit for the implement). So the ORC will not keep you from exceeding 540 rpm at the PTO.

 

[Anonymous-0]

Lots of good ideas/suggestions below. Replace the whole thing and get the 1-3/8 shaft. The ORC is a safety device. GOod too have. However. The ORC will lengthen the PTO shaft even and cause the PTO implements to push on the PTO shaft even worse and wear everything out again. We discovered this on our 9N that came with a mower and ORC. If the mower PTO was any longer it wouldn"t have been able to mount to the tractor. You may have to cut the mower PTO to the right length.
GOod luck.